OLED Panel with Earth Metal Dopants for Balanced Charge Mobility
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Solution Overview
Problem
In organic light-emitting diodes, the difference in hole and electron mobility leads to a deviation of recombination centers, reducing light-emitting efficiency as the recombination center is not within the organic light-emitting layer.
Innovation Solution
The organic light-emitting display panel incorporates a first electron transmission layer with an alkaline earth metal or rare earth metal dopant and a hole injection layer with a specific dopant, ensuring that the energy level differences between molecular orbitals facilitate balanced electron and hole mobility, allowing recombination to occur within the organic light-emitting layer.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional organic light-emitting diode structure is used, then device simplicity is maintained, but hole and electron mobility are unbalanced causing recombination center deviation
Solution Approach 1:
The organic functional layer is segmented into multiple sub-layers: hole injection layer, electron transmission layer, and light-emitting layer. Each sub-layer is optimized independently with specific dopants to control charge carrier injection and transport, ensuring balanced mobility while maintaining overall device functionality.
Solution Approach 2:
Different regions of the organic functional layer are assigned different materials and dopant concentrations tailored to local requirements. The hole injection layer uses materials optimized for hole injection, the electron transmission layer uses materials optimized for electron transport, and the light-emitting layer contains the emissive compounds, creating locally optimized properties throughout the structure.
2Reliability
If electron transmission layer with alkaline earth metal or rare earth metal dopant is added, then electron mobility is improved, but device structure becomes more complex
Solution Approach 1:
The electron transmission layer combines multiple functions into a single layer: electron injection from cathode, electron transport toward the light-emitting layer, and energy level matching. By using alkaline earth metal or rare earth metal dopants, the layer simultaneously achieves high electron mobility and proper energy level alignment without requiring additional separate layers.
Solution Approach 2:
The electron transmission layer utilizes parameter changes through dopant concentration optimization and energy level matching. By carefully selecting dopant types and concentrations, the layer's electrical and optical parameters are tuned to achieve balanced charge transport while maintaining structural simplicity.
3Reliability
If hole injection layer with specific dopant is added, then hole mobility is improved, but device structure becomes more complex
Solution Approach 1:
The hole injection layer merges hole injection from anode, hole transport toward the light-emitting layer, and energy level matching into a single functional layer. Specific dopants are incorporated to simultaneously enhance hole mobility and ensure proper energy level alignment with adjacent layers, eliminating the need for additional structural complexity.
Solution Approach 2:
The hole injection layer achieves optimized hole transport through parameter changes in dopant selection and concentration. By tuning these parameters, the layer provides both high hole mobility and proper energy level matching, resolving the mobility imbalance without increasing structural complexity.
4Reliability
If energy levels are optimized to balance charge mobility, then light-emitting efficiency is improved, but manufacturing precision requirements increase
Solution Approach 1:
The energy levels of adjacent layers are designed to be equipotential or nearly equipotential at their interfaces. The hole injection layer, electron transmission layer, and light-emitting layer are engineered with energy levels that match smoothly, creating equipotential conditions that facilitate balanced charge carrier injection and transport without requiring extreme manufacturing precision.
Solution Approach 2:
Energy level matching is achieved through systematic parameter changes in material selection and dopant concentrations. By adjusting these parameters within reasonable ranges, the patent achieves proper energy level alignment that is robust to manufacturing variations, reducing the stringency of precision requirements while maintaining high light-emitting efficiency.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This configuration balances electron and hole mobility, preventing recombination center deviation and enhancing light-emitting efficiency by ensuring electrons and holes recombine within the organic light-emitting layer.
Implementation Method 1
a first electron transmission layer disposed between the cathode and the organic light-emitting layer, and a hole injection layer disposed between the anode and the organic light-emitting layer. The first electron transmission layer includes an electron transmission matrix and a first dopant, the first dopant includes an alkaline earth metal element or a rare earth metal element
Implementation Method 2
The organic light-emitting diode emits light through a light-emitting layer disposed between an anode and a cathode under an electric field applied between the anode and the cathode
Implementation Method 3
The first electron transmission layer includes an electron transmission matrix and a first dopant, the first dopant includes an alkaline earth metal element or a rare earth metal element, and the hole injection layer includes a hole injection matrix and a second dopant
Data Source
AI summary
Provided are an organic light-emitting display panel and a display device. The organic light-emitting display includes an array substrate and organic light-emitting components each having an anode, a cathode and an organic functional layer. The organic functional layer includes an organic light-emitting layer, a first electron transmission layer, and a hole injection layer. LUMO1 and LUMO4 satisfy: |LUMO1−LUMO4|<1.7 eV. HOMO5 and HOMO4 satisfy: |HOMO5−HOMO4|<1 eV. A work function φ1 of the first dopant and a work function φ4 of the cathode satisfy: φ1<φ4, and a work function φ2 of the second dopant and a work function φ3 of the anode satisfy: φ2>φ3.